i2c: mux: gpio: Check gpio_direction_output return value

gpio_direction_output() may fail, check for that and deal with it
appropriately. Also log an error message if gpio_request() fails.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Peter Korsgaard <peter.korsgaard@barco.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

diff --git a/drivers/i2c/muxes/i2c-mux-gpio.c b/drivers/i2c/muxes/i2c-mux-gpio.c
index abc2e55..5a0ce00 100644 (file)
--- a/drivers/i2c/muxes/i2c-mux-gpio.c
+++ b/drivers/i2c/muxes/i2c-mux-gpio.c
@@ -201,10 +201,21 @@ static int i2c_mux_gpio_probe(struct platform_device *pdev)
 
        for (i = 0; i < mux->data.n_gpios; i++) {
                ret = gpio_request(gpio_base + mux->data.gpios[i], "i2c-mux-gpio");
-               if (ret)
+               if (ret) {
+                       dev_err(&pdev->dev, "Failed to request GPIO %d\n",
+                               mux->data.gpios[i]);
                        goto err_request_gpio;
-               gpio_direction_output(gpio_base + mux->data.gpios[i],
-                                     initial_state & (1 << i));
+               }
+
+               ret = gpio_direction_output(gpio_base + mux->data.gpios[i],
+                                           initial_state & (1 << i));
+               if (ret) {
+                       dev_err(&pdev->dev,
+                               "Failed to set direction of GPIO %d to output\n",
+                               mux->data.gpios[i]);
+                       i++;    /* gpio_request above succeeded, so must free */
+                       goto err_request_gpio;
+               }
        }
 
        for (i = 0; i < mux->data.n_values; i++) {